摘要:

AbstractThe volatile products of thermal degradation of copolymers of methyl methacrylate and butyl acrylate covering the entire composition range have been identified. 1‐Butene and carbon dioxide are the main gaseous products. Other products, methane, ethane, propane, butane, ethylene, propylene,cisandtrans2‐butene, hydrogen and carbon monoxide are also present in very small amounts which tend to increase with the butyl acrylate content of the copolymer. The liquid products are butanol, methyl methacrylate, butyl acrylate and butyl methacrylate.Products have been estimated quantitatively for all the copolymers at intervals during the course of the reaction and detailed mass balance tables drawn up.The yields of carbon dioxide and 1‐butene and the molar ratio of carbon dioxide to 1‐butene all increase with increasing acrylate content of the copolymer. Methyl methacrylate is the only liquid product from high methacrylate copolymers. Butyl acrylate and methacrylate begin to appear in 16,3 mole‐% butyl acrylate copolymer although butanol is still absent. From high acrylate copolymers butanol is the only liqui

ISSN:0025-116X    

DOI:10.1002/macp.1973.021680101

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe residual material after thermal degradation of copolymers of methyl methacrylate and butyl acrylate, covering the entire composition range, has been investigated. High methacrylate copolymers remain soluble in carbon tetrachloride. Increasing acrylate content makes the residue increasingly insoluble. The absorption which appears in the IR spectrum of the residual polymer at 1560 cm−1is associated with the formation of a carboxylate ion whereas a shoulder on the carbonyl peak at 1760 cm−1is ascribed to lactone formation. Absorption at 1605 cm−1in the IR spectrum and in the 420–227 nm region of the UV spectrum are attributed to conjugated carbon‐carbon unsaturation.Chain scission in low acrylate copolymers and crosslinking in high acrylate copolymers are both closely associated with the acrylate content of the copolymer but there is no one to one relationship between chain scission and carbon dioxide production as there was in the methylmethacrylate/methyl acrylate copolym

ISSN:0025-116X    

DOI:10.1002/macp.1973.021680102

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractLes monomères cités ont été copolymérisés radicalairement dans le benzene avec le styrène. La composition des copolymères a été déterminée à partir de leurs spectres NMR. Les constantesr1etr2été détérminée d calculdes; dans ce cas, lesp‐vinylbenzopédnones méthoxy‐lées ont une plus grande réactivité que le styrene. Les homo et copolymkres de cesp‐vinyl‐benzophdnones n'ont aucun effet protecteur contre le rayonnement UV. La condition nécessaire pour obtenir cet effet est la pédsence d'un groupement hydroxyle en positionorthopar rapport au groupement carbonyle. La déméthylation partielle des polyméres des vinyl‐4 méthoxy‐2′ benzophénones a été étudiée dans ce but. Cette réaction a permis d'obtenir en particulier la poly(viny1‐4 hydroxy‐2′ mdthoxy‐4′ benzophenone) dont le spectre U

ISSN:0025-116X    

DOI:10.1002/macp.1973.021680103

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractVinyl trifluoroacetate was polymerized by free radicals in various aldehydes at temperatures between −40 and 60°C. The syndiotactic and isotactic diad contents of the polymer were determined through the triads obtained by NMR spectra. The differences of activation enthalpies and entropies of isotactic and syndiotactic arrangement were calculated from the temperature dependence of the ratio of isotactic and syndiotactic diads. In the case of the applied aldehydes, a compensation effect exists between the two quantities, the values of which differ from the values of alkanes, vinyl trifluoroacetate, esters and ketones. The syndiotactic diads of a polymer prepared in aldehydes at 60°C vary from 54 to 56% and are higher than those for the other solvents (50–53%), but the temperature dependence is scarcely low. We consider that the interaction between the fluor atoms in the trifluoroacetyl group of vinyl trifluoroacetate and the π‐bond in the aldehyde affect the stereore

ISSN:0025-116X    

DOI:10.1002/macp.1973.021680104

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractIn order to obtain a linear poly(1,3,4‐oxadiazole‐2,5‐diyl) the self‐polycondensation of oxalyl dihydrazide has been investigated. Polymers with molecular weight up to 6000 were prepared by solution polycondensation inN‐methylpyrrolidone containing lithiumchloride. These polymers are thermally stable up to 300°C. They were characterized by IR spectra, thermal analysis and so

ISSN:0025-116X    

DOI:10.1002/macp.1973.021680105

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe reaction of chlorine or nitrogen dioxide with polybutadienes consists mainly in their addition to the double bonds of the polymer, but it is often followed by a number of secondary reactions, such as crosslinking andcis‐transisomerization.The effects of polymer microstructure, nature of the solvent, solution concentration, temperature, and various additives, are studied. To explain the experimental facts several reaction mechanisms are proposed.The chlorination reaction is thought to follow an ionic and radical mechanism simultaneously. The former, which is always predominant, gives only soluble addition products without secondary reactions, whereas the latter can give rise to crosslinked and isomerized products, besides the addition product. Under certain experimental conditions the radical reaction can be avoided and only soluble addition products are obtained.The reaction with nitrogen dioxide is predominantly of radical character, and consequently it is always followed by isomerization and crosslinking reactions. Only under special conditions these ancillary reactions can be avoide

ISSN:0025-116X    

DOI:10.1002/macp.1973.021680106

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractBy action of pyridine, maleimide undergoes polymerization in water at room temperature. The polymers formed have low molecular weights (Mnbetween 500 and 1000) and their structure seems to involve predominantly succinimide type units.

ISSN:0025-116X    

DOI:10.1002/macp.1973.021680107

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe reaction of benzoyl peroxide with 2,5‐dichloro‐1,4‐benzoquinone and 2,3,5,6‐tetrachloro‐1,4‐benzoquinone (chloranil) in chlorobenzene was studied by isolation and identification of the reaction products.In dilute solution (0,02 mol peroxide/dm3), both phenyl and benzoyloxy radicals interact with 2,5‐dichloro‐1,4‐benzoquinone to form the corresponding quinonoid derivatives by substitution of hydrogen atoms in the quinone nucleus. Chloranil does not react under these conditions.In concentrated solution (0,5 mol peroxide/dm3), both 2,5‐dichloro‐1,4‐benzoquinone and chloranil are attacked by radicals of the spontaneous as well as the induced decomposition of the peroxide. Aryl radicals (but not benzoyloxy radicals) can substitute only one chlorine atom of the chloranil molecule. The difficulty is due to the steric hindrance of the chlorine atoms and the instability of the radical intermediate. This probably accounts for the tendency of chloranil to react with polymeric radicals through

ISSN:0025-116X    

DOI:10.1002/macp.1973.021680108

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractThe reaction between benzoyl peroxide andp‐benzoquinone in CCl4was investigated by isolation and identification of the reaction products. At peroxide/quinone ratios ≥ 3 only quinonoid products of the spontaneous decomposition of the peroxide are formed. At ratios<3 the peroxide undergoes induced decomposition by both trichloromethyl and phenyl radicals. The induced decomposition involves the formation of radical intermediates which undergo intermolecular disproportionation, but not intramolecular rearrangement to formp‐trichloromethylbenzoyloxy radicals,p‐phenylbenzoyloxy radicals, and their corresponding acids. Thep‐trichloromethylbenzoyloxy radicals are captured by benzoquinone to form 2‐(p‐trichloromethylbenzoyloxy)‐1,4‐benzoquinone and a considerable amount of quinonoid resins. A correlation between the electron‐donating or accepting property of a radical and its capability to induce the decomposition of the per

ISSN:0025-116X    

DOI:10.1002/macp.1973.021680109

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY

摘要:

AbstractEin neues Initiierungssystem, das aus einem einkernigen Komplex von einwertigem Rhodium und Diacylperoxid bzw. Hydroperoxid besteht, wurde untersucht. Die Abhängigkeit der Polymerisationsgeschwindigkeit des Methylmethacrylats und des durchschnittlichen Polymerisationsgrades vom Molverhältnis Rhodium‐Komplexverbindung zu Peroxid, von der Temperatur und von der Viskosität des Lösungsmittels wurde bestimmt und die Taktizität der entstandenen Polymeren verfolgt. Der Mechanismus der durch das betrachtete Initiierungssystem ausgelösten Polymerisation von Methylmethacrylat wird dis

ISSN:0025-116X    

DOI:10.1002/macp.1973.021680110

出版商:Hüthig&Wepf Verlag    

年代:1973

数据来源: WILEY